1. Field of the Invention
The present invention relates to a rapid exchange catheter, such as a fluid jet material removal catheter and system, to a method of constructing same, and to a method of using same in diagnosis or treatment of a body vessel or other body cavity or tissue.
The present invention relates to apparatus for use in treatment of the human body. More particularly, the present invention relates to an elongated device which may be a single catheter assembly or a multiple component catheter assembly and which is suitable for use through percutaneous or other access, for endoscopic procedures, or for intraoperative use in either open or limited access surgical procedures. Still more particularly, the present invention relates to an elongated device in the form of a fluid jet thrombectomy catheter, being adapted for fragmentation and removal of thrombus or other unwanted material from blood vessels or body cavities by using high velocity saline (or other suitable fluid) jets to macerate the thrombus or other unwanted material. The elongated device bears certain similarities to known waterjet thrombectomy catheter devices and can be used as such, but differs therefrom in several material respects, with major differences being the construction of the device from simpler tubular components, utilization of a semi-rigid intermediate tube to facilitate transition between a guidewire-containing and a non-guidewire-containing portion, and enhanced utility of the device in rapid exchange methods with a single operator. The device is particularly advantageous in a cross stream configuration but can be adapted to other forms as well. The cross stream jets create a recirculation flow pattern optimized for clearing a large cross section of mural thrombus or other similar material. Further, the present invention also relates to a system constituted either by the combination of the elongated device with both pressurized fluid source means and exhaust regulation means or by the combination of the elongated device with only pressurized fluid source means. Other ancillary devices or features can be utilized or incorporated such as introduction devices, guiding devices, isolation or filtering devices, centering devices, imaging devices, infusion or withdrawal devices, dilatation devices, energy delivery devices, and so forth, to aid in diagnosis or treatment of a patient, without departing from the scope of the present invention. The use of a semi-rigid intermediate tube can be applied to other elongated devices such as intravascular catheters, balloon catheters, device delivery catheters, and so forth, and is not limited solely to fluid jet material removal catheters.
2. Description of the Prior Art
Procedures and apparatus have been developed for ease in removing tissue and various deposits. Several such devices employ a jet of saline as the working tool to help break up the tissue deposit and further provide a suction means to remove the deposit. U.S. Pat. No. 5,135,482 to Neracher describes a hydrodynamic device for removal of organic deposit from a human vessel. A supply of saline is delivered by a high pressure duct to the distal end of a catheter. The saline exits the duct as a jet that is directed generally forward and directly toward the tissue to be broken up. The duct is contained within and can move axially with respect to a hose that is positioned around the duct. A vacuum suction is applied to the hose to remove the debris that is created from the broken-up tissue. There is no guidewire lumen and no provision for rapid exchange of the device over a guidewire.
Another drainage catheter, described by Griep in U.S. Pat. No. 5,320,599, has a discharge channel and a pressure channel. The channels are formed into a single catheter tube such that the two tubes are fixed with respect to each other. This device does not have a guidewire lumen and cannot be used as a rapid-exchange wire-guided device.
Waterjet thrombectomy catheters have been described (including U.S. Pat. Nos. 5,370,609, 5,989,210, 6,096,001 and 6,224,570) in which a distal-to-proximal directed waterjet(s) flow(s) past a window, orifice or gap at the distal end of the catheter, re-entering the catheter and pushing flow through an evacuation lumen. When placed in a vessel containing thrombus and activated, the high velocity jet(s) will entrain surrounding fluid and thrombus into the window, orifice or gap region, where the high shear forces of the jet(s) will macerate the thrombus. The macerated particles will be removed from the body by the pressure generated on the distal end of the evacuation lumen by the impingement of the high velocity waterjet(s).
A limitation of these waterjet thrombectomy catheters has been the inability to remove organized, wall-adherent thrombus from large vessels. In accordance with the present invention, the rapid exchange fluid jet thrombectomy device described overcomes this limitation by utilizing cross stream jets to optimize the recirculation pattern at the tip of the device and increase the drag force exerted on the mural thrombus to break it free from the vessel wall and allow it to be removed by the device.
Prior art devices often required the use of more than one operator where one operator must stabilize the guidewire while the second operator introduces the catheter over the guidewire into the anatomy. Various approaches have been used to overcome this difficulty, with varying degrees of success. Bonzel U.S. Pat. No. 4,762,129, Yock U.S. Pat. No. 5,040,548, Keith U.S. Pat. No. 5,156,594, Keith et al. U.S. Pat. No. 5,370,616, Horzewski et al. U.S. Pat. No. 5,496,346, Enger U.S. Pat. No. 5,728,067, and Enger U.S. Pat. No. 5,980,486 disclose balloon catheters which include a short guidewire lumen near the distal end, to provide for rapid or single-operator exchange. The Bonzel patent discloses a balloon catheter which has a short guidewire lumen only passing through a distal balloon and alongside a balloon inflation lumen which terminates in the balloon; this approach is not appropriate for a cross stream type fluid jet catheter where internal pressure would cause a significant leakage from the exhaust lumen through the proximal opening of the guidewire lumen and into the vessel, and a side-by-side asymmetric configuration would cause the guidewire or guidewire lumen to interfere with access of the jets or the cross stream jets to the thrombus and would be stiffer, thereby not being able to track as well. The Yock patent discloses a balloon catheter with a guidewire lumen which extends some distance proximal to the balloon, with the proximal and distal inflation lumens and guidewire lumen being preferably of flexible plastic material; the Yock device lacks a semi-rigid intermediate tube which provides reliable geometry to ensure free guidewire movement in this region, and provides a more efficient yet controllable fabrication. As with the Bonzel and Yock devices, the Keith et al., Horzewski et al., and Enger devices are balloon catheters not adapted for fluid jet thrombectomy. The present invention provides a high-pressure supply lumen to supply the fluid jets, and an exhaust lumen for removal of thrombus or unwanted tissue debris, both extending along the length of the device, in addition to a shorter guidewire lumen extending only a portion of the length of the device. None of the prior art devices provides these three lumens to provide the form or function of the present invention.
Co-pending application Ser. No. 09/888,455, assigned to the same assignee as the present invention, discloses a fluid jet thrombectomy catheter which is adapted for single operator exchange. That device provides an interchangeable system where one inner catheter assembly containing fluid jet orifices can be substituted for a different inner catheter assembly according to the particular requirements of the material removal procedure in the vasculature. However, that device requires two separate components, resulting in compatibility and alignment issues necessitating more complex designs with alignment stops and more expensive fabrication than the present design, and requires additional manipulations by the physician to utilize the device. When such interchangeable inner catheter assemblies are not required, the present invention provides a simpler unitary device with more straightforward operation.
The present invention overcomes complexities of the prior art by introducing a semi-rigid intermediate tube which connects a distal exhaust tube, a guidewire lumen, and a proximal exhaust tube in an efficient and easily fabricated configuration, and provides reliable operation over a guidewire and which is applicable for removal of unwanted deposits in the body, such as, but not limited to, thrombus in a blood vessel or cardiac chamber or extravascular space, renal or biliary deposits, hematomas in the brain or brain ventricles or elsewhere, material in the gastrointestinal tract, material in the respiratory tract or lungs, or material associated with a joint, for example. The present invention is particularly useful in a fluid jet thrombectomy device.
The present invention also includes a rapid exchange fluid jet system, and a semi-rigid intermediate tube, and a method of fabricating a multiple-lumen rapid exchange catheter, and a method of removing unwanted tissue from the body using a rapid exchange fluid jet catheter and system.